Water must be available for the operation of some components in a power plant. By way of example, in a steam electric power plant, a large quantity of water is required for the water-steam circuit in order to generate the necessary quantity of operating and auxiliary steam.
Further, a water reservoir must be replenished continuously during operation as the amount of water in the water-steam circuit decreases due to losses.
The provision or replenishment of water for power plants is, as a rule, easy to achieve in areas where there are adequate water sources or where a well developed supply system has been implemented.
By contrast, in regions ill supplied with water, the provision and maintenance of the amount of water necessary for the operation of the power plant is more problematic.